The home sale exclusion lets you omit from gross income up to $250,000 of gain ($500,000 on a joint return), but only if you meet certain conditions:
Advance payment of current tax liability based either on wage withholdings or installment payments of your estimated tax liability. To avoid penalties, you generally must pay to the IRS either 90% of your final tax liability, or either 100% or 110% of the prior year’s tax liability, depending on your adjusted gross income.